JPH11285942A - Method and device for releasing over-travel of servo shaft - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make OT(over-travel) release upon deciding the sequence of OT release automatically even in the case where the arrangement includes a plurality of servo shafts. SOLUTION: This device is to release a plurality of servo shafts having traveled beyond the specified range so that the operation is made practicable, and when an over-travel release switch 71 and a JOG switch 73 are pushed, a control device 63 performs the release by giving commands for movement for the specified releasing amounts to the servo motors 81 of the respective shafts through a command part 79 in conformity to the sequence preset and stored in a memory 77, so that the operator is not required to pass judgement and easy return can be made. To the servo motors 81, the control device 63 gives commands as the releasing amounts a distance at least longer than the distance from sensing of an occurrence of over-travel to stopping actually, so that the axes can be returned certainly to the range where movement is practicable.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a servo axis overtravel release method and apparatus for releasing overtravel when a plurality of servo axes enter an overtravel state and stop.

[0002]

2. Description of the Related Art FIG. 4 shows an axis moving mechanism 101 generally used for a machine table, a carriage and the like.
It is shown. In the shaft moving mechanism 101, a ball screw 105 rotated by a servo motor 103 is rotatably provided, and a moving body 109 having a ball nut 107 screwed to the ball screw 105 is movably provided. At both ends of the ball screw 105, in order to limit the movement range in which normal movement / positioning is possible,
Limit switches 111 and 113 are provided.

In such a moving mechanism 101, the moving body 109 has exceeded the moving range ("overtravel";
Hereinafter, it is indicated by “OT”).
1, 113, the machine is stopped immediately. In order to release this state, for example, when the movement range of the X axis is exceeded, the X axis is selected by an axis selection switch (not shown), and the JOG switch is pressed and released while pressing the OT release switch. It is.

[0004]

However, such a conventional technique has a problem that in the case of a machine having a large number of axes, the corresponding axis must be selected with an axis selection switch, which is troublesome. Also, when a plurality of axes are simultaneously OT, if the OT release of the OT axis has an order, the operator must remember the OT release order, which is complicated. For this reason, processing must be performed while looking at the instruction manual, resulting in poor work efficiency.

SUMMARY OF THE INVENTION An object of the present invention is to focus on the conventional technology as described above. Even in the case of a plurality of axes, the servo axis can be released according to a predetermined OT release order. It is to provide a travel release method and its device.

[0006]

In order to achieve the above object, a method for releasing an overtravel of a servo axis according to the first aspect of the present invention comprises the steps of: When the JOG switch is pressed together with the overtravel release switch in the overtravel release method of the servo axis for releasing and enabling operation, the control device performs the overtravel release according to a preset release sequence. , Is characterized.

Therefore, when the overtravel switch and the JOG switch are pressed when releasing a plurality of axes that have been overtraveled beyond the movement range and are operable, the control device sets a preset value. Release multiple axes according to the order in which they are performed.

According to a second aspect of the present invention, there is provided an overtravel release apparatus for a servo axis for releasing a plurality of axes which are stopped due to overtravel occurring beyond a moving range and enabling operation. An overtravel release switch for instructing overtravel release of the plurality of axes, a JOG switch for automatically instructing release of overtravel, and a release device for controlling the overtravel and release of the plurality of axes. And a control device for performing overtravel release in a preset order for the plurality of axes when the switch and the JOG switch are pressed, wherein the control device stores a release order for the plurality of axes. Command for the release amount to the memory A command unit that is configured to characterized in that it comprises a.

Therefore, when the overtravel switch and the JOG switch are depressed when releasing a plurality of axes which are in the overtravel state beyond the moving range and enabling the operation, the control device sets a preset value. Then, in accordance with the order stored in the memory, a command is issued to each axis servomotor via a command unit to return the servomotor by a predetermined release amount, and release is performed.

According to a third aspect of the present invention, there is provided an overtravel release device for a servo shaft, wherein the control device in the overtravel release device for the servo shaft according to the second aspect is configured such that:
The release amount is set to be at least longer than the distance from when the occurrence of overtravel in each axis is detected to when the overtravel actually stops.
It is characterized by the following.

Accordingly, the control device instructs each axis servomotor to have a release amount at least longer than the distance from the occurrence of overtravel to the actual stop.

[0012]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 3 shows a bending machine 1. The folding machine 1 includes a lower frame 3 that supports the whole, and a front plate 5 is provided at a front portion (right side in FIG. 3) of the lower frame 3. At the upper end of the front plate 5, a bottom die 7 is provided.

Above the lower frame 3, there is provided an upper frame 11 which is rotatable in a vertical direction with a hinge pin 9 provided at the rear (left side in FIG. 3) as a fulcrum. A plate holding plate 13 is integrally provided at a front portion of the upper frame 11, and a top die 15 facing the bottom die 7 is provided at a lower end of the plate holding plate 13.

The upper frame 11 is provided with a Z-axis servomotor 17 as a clamping motor. A drive pulley 19 is mounted on the output shaft of the Z-axis servo motor 17, and a driven pulley 21 is rotatably supported above the plate holding plate 13.
A belt 23 is wound around 1 and the driving pulley 19.

The driven pulley 21 has a crankshaft (Z
A shaft 25 is provided, and the upper end of a connecting arm 27 having a bow shape is rotatably attached to the crank shaft 25 via a pin 29. The lower end of the connecting arm 27 is connected to the front plate 5.
Is rotatably mounted via a pin 31.

When the Z-axis servomotor 17 is driven, the crankshaft 25 is driven via the driving pulley 19, the belt 23, and the driven pulley 21. When the crankshaft 25 is driven, the connecting arm 27 swings with the pin 31 as a fulcrum due to the reaction force. As a result, the upper frame 11 rotates vertically with the hinge pin 9 as a fulcrum, and the top die 15
Moves up and down.

When the top die 15 is lowered in this way, the work W placed on the bottom die 7 is clamped between the bottom die 7 and the top die 15.

Inside the lower frame 3, a bending die 33 for bending the work W clamped by the bottom die 7 and the top die 15 upward or downward is provided. The bending mold 33 includes an upper bending mold 33U and a lower bending mold 33D. This upper bending mold 33U
And the lower bending mold 33D are attached to the bend beam 35.

An eccentric shaft (AL / AR axis) 39 rotated by an AC servomotor 37 is provided at the rear of the bend beam 35.
Thus, it is rotatably mounted on the front part of the bending frame 41. An eccentric shaft (A-axis) 43 is mounted on the bending frame 41, and a driven pulley is attached to the eccentric shaft 43.

An A-axis servo motor 45, which is a clearance adjusting motor, is mounted on the lower frame 3. A driving pulley 47 is mounted on an output shaft of the AC servo motor 45 for adjusting the clearance. A belt 49 is wound around the driving pulley 47 and the driven pulley.

An upper end of an arm member 51 is attached to a lower portion of the bend beam 35, and a crank shaft (D axis) 53 is rotatably provided at a lower end of the arm member 51. The crankshaft 53 has a gear 5
The gear 55 meshes with a drive gear 59 of a D-axis servomotor 57 which is a bend motor attached to the lower frame 3.

Since the AC servo motor 45 for adjusting the clearance is driven,
The eccentric shaft 43 is rotated via the driving pulley 47, the belt 49, and the driven pulley, whereby the bending die frame 41 moves in the left-right direction in FIG.
Alternatively, the clearance with the bottom die 7 is adjusted.

In the AL / AR shaft, the AC servomotor 37 rotates the AL / AR shaft (eccentric shaft) via a speed reducer (not shown), so that the bending die 33 and the top die 15 or the bottom die 7 are rotated. Adjust the change between the center and left and right of the clearance.

When the D-axis servo motor 57 is driven, the crankshaft 53 is driven via the drive gear 59 and the gear 55.
Rotates, and the bend beam 35 rotates about the eccentric shaft 39 as a fulcrum. As a result, the workpiece W clamped by the bottom die 7 and the top die 15 is
Forward bending or reverse bending is performed by the 3U or downward bending mold 33D.

FIG. 1 shows a servo shaft overtravel release device 61 according to the present invention. The overtravel / release device 61 has a control device 63 for controlling each axis.

The control unit 63 has a CPU 65 as a central processing unit. The CPU 65 has input means such as a keyboard for inputting data necessary for operating the machine and selecting necessary items. 67 and an output means 69 such as a CRT or a liquid crystal panel for displaying the input value from the input means 67 and the state of the machine.

Further, an operation switch unit 75 for instructing start and stop of the machine operation and having various switches such as an OT release switch 71 and a JOG switch 73 is connected.

Also, the CPU 65 issues a memory 77 which stores the order of axes to be released when a plurality of axes are overtraveled at the same time and various data, a position command for moving each axis, and the like. A command unit 79 is connected and controls each axis servomotor 81. Position information from an encoder 83, which is a position detecting means mounted on each axis servo motor 81, is fed back to the control device 63 so as to perform accurate positioning.

Further, in order to check the operation state of the machine, the CPU 65 notifies each axis + OT sensor 85 and each axis -OT for notifying the plus and minus movement limits of each axis.
An OT sensor 87 and a sensor unit 89 having a confirmation sensor and the like are connected.

Next, an overtravel release method of the servo axis will be described with reference to FIG.

During operation of the machine, when the axis moves to the stroke end due to a data input error, an operation error, or the like (step S1), each axis + OT sensor 85 or each axis-OT sensor 87 at the stroke end is turned on. And the machine stops and the overtravel release device 6
1 detects overtravel of the axis (step S
2).

Since the overtraveling axis must be released in order to enable the operation of the machine, the controller 63 which has detected the overtravel of the axis requires an O.
The axis that needs to be released by T is selected (step S3). Here, when the OT alarms are simultaneously generated for a plurality of axes, the OT is released according to the order of the axes set in advance and stored in the memory 77 so that the axes can be operated (step S4). For example, priorities are set in advance as A axis → D axis → Z axis in the bending machine 1 shown in FIG.

When the control unit 63 detects that the OT release switch and the JOG switch are pressed, the command unit 79
The servo motor 81 is instructed to release the OT via the command (step S5). As the release amount at this time, at least a distance longer than a distance from when the occurrence of overtravel is detected to when the overtravel is actually stopped is used to instruct each axis servomotor. The distance may be controlled by the rotation amount of the servo motor 81.

If OT alarms have occurred for a plurality of axes, it is determined whether or not OT release has been completed for all axes (step S6). Repeat step S5 of
Perform T release. If the OT release has been completed for all axes, the OT release is ended (step S
E).

From the above results, when overtravel of a plurality of axes occurs simultaneously in a complicated machine having a large number of axes, and the order and method of OT release are limited, the overtravel / release device 61 makes intelligent judgment. And
OT release can be performed only with the OT release switch and the JOG switch.

Thus, the portion determined by the operator is reduced, and the overtravel can be easily restored.

The present invention is not limited to the above-described embodiment, but can be embodied in other modes by making appropriate changes.

[0039]

As described above, the servo axis overtravel release method according to the first aspect of the present invention
When the overtravel switch and the JOG switch are pressed when releasing a plurality of axes that have been overtraveled beyond the movement range and the operation is enabled, the control device operates in a predetermined order. Since the release of a plurality of axes is performed, it is possible to easily return without the judgment of the operator.

In the apparatus for releasing an overtravel of a servo axis according to the second aspect of the present invention, when releasing a plurality of axes in an overtravel state beyond the moving range to enable the operation, an overtravel switch and a JOG are used. When the switch is pressed, the controller issues a command to move each axis servomotor by a predetermined release amount via the command unit in accordance with the order set in advance and stored in the memory, and performs the release. Thus, it is possible to easily return without the judgment of the operator.

In the overtravel release device for a servo axis according to the third aspect of the present invention, the control device sets each axis as a release amount at least longer than the distance from the detection of the occurrence of overtravel to the actual stop. Since a command is given to the servomotor, each axis can be reliably returned to the movable range.

[Brief description of the drawings]

FIG. 1 shows the overtravel of a servo shaft according to the present invention.
It is a block diagram showing a release device.

FIG. 2 shows the overtravel of the servo shaft according to the present invention.
It is a flowchart which shows a release method.

FIG. 3 is a side view showing the entire bending machine having a servo shaft to which the present invention is applied;

FIG. 4 is a partially omitted front view showing a general shaft moving mechanism.

[Explanation of symbols]

 61 Overtravel / release device 63 Control device 71 Overtravel / release switch 73 JOG switch 77 Memory 79 Command section

Claims (3)

[Claims] An overtravel release method for a servo axis for releasing a plurality of axes that have stopped due to overtravel occurring beyond a moving range and a JOG together with an overtravel release switch.
When the switch is pressed, the control device performs an overtravel release in accordance with a preset release sequence, and the overtravel release method for the servo axis. 2. An overtravel release device for a servo axis for releasing a plurality of axes that have stopped due to overtravel occurring beyond a movement range, said overtravel release of said plurality of axes. An overtravel release switch for instructing release of the overtravel, a JOG switch for automatically releasing overtravel, and controlling the plurality of axes, and the plurality of axes are controlled when the overtravel switch and the JOG switch are pressed. A control device that performs overtravel release in a preset order for the plurality of axes, the control device stores a release order for the plurality of axes, and a release amount command to each axis servomotor. And a command unit for performing servo control. Bell release device. 3. The control device according to claim 2, wherein the release amount is set to a distance at least longer than a distance from the occurrence of overtravel in each axis to the actual stop. Claim 2
Overtravel release device for servo axis as described.